Target assembly system and method

ABSTRACT

A target system and method for photogrammetry using a target holder with an aperture at least partially therethrough to precisely position a target assembly therein for use in determining geometric properties of an object.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part to co-pending U.S.application Ser. No. 12/612,565, filed Nov. 4, 2009 and which claimspriority pursuant to 35 U.S.C. 119(e) to U.S. Provisional PatentApplication Ser. No. 61/111,243, filed Nov. 4, 2008, the entiredisclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present general inventive concept relates to a target system andmethod to be used in photogrammetry, and in one particular embodiment,to a target holder having an aperture at least partially therethrough toprecisely position a target assembly therein for use in determininggeometric properties of an object. In another embodiment, the generalinventive concept relates to a target holder including an annularprotruding rim and a generally flat surface for placement of a targetpiece (such as a target paper material). In still another embodiment,the general inventive concept relates to a method of placing a targetpiece on a target holder.

2. Description of the Related Art

A large number of industries require precise and accurate measuring fora number of applications such as production, manufacturing, and processcontrol. In many such applications, measurement errors on the order ofeven one ten-thousandth of an inch can be critical. Instruments such aslaser trackers, scanners, associated targets and the like areparticularly well suited for such applications because they provideextreme precision and accuracy.

Retro-reflective photogrammetric target systems have been designed, suchas the system disclosed by U.S. Pat. No. 5,073,005, the entiredisclosure of which is incorporated herein by reference, for precisemeasurement application. Nevertheless, the target structure of U.S. Pat.No. 5,073,005 provides significant challenges during manufacturing, asminor imprecision during the assembly of a single component (such as amask over a reflective material of the target) can result in significantinaccuracy of the target during usage Therefore, it would be desirableto provide a target structure that can be assembled with lesspossibility of resulting in inaccuracies of the target during usage.

SUMMARY OF THE INVENTION

The present general inventive concept provides an improved target systemand method to be used in photogrammetry. In one particular embodimentthe general inventive concept provides a target holder having anaperture therethrough to precisely position a target assembly thereinfor use in determining geometric properties of an object. In anotherembodiment, the general inventive concept relates to a target holderincluding an annular protruding rim and a generally flat surface forplacement of a target piece. In still another embodiment, the generalinventive concept relates to a method of placing a target piece on atarget holder.

The present general inventive concept further provides a target assemblywith improved accuracy.

The present general inventive concept further provides a target assemblythat protects a target piece by recessing the target piece into thetarget assembly.

The present general inventive concept further provides, in a preferredembodiment, a target assembly with elements that magnetically engageeach other thereby eliminating the need to handle elements that aresensitive to touch such as reflective paper.

The present general inventive concept further provides, in a preferredembodiment, a target assembly having a flat disk to receive a removabletarget piece.

The present general inventive concept further provides a target paperthat is attached to a flat disk via an adhesive, static, and/or magneticattachment means.

The present general inventive concept further provides, in a preferredembodiment, a target having a mask that is attached by means thatprevent creep or other undesired movement of the mask, which overcomesthe problem of traditional vinyl masks that are attached by an adhesivethat results in eventual creep and inaccuracy of the target.

The present general inventive concept further provides, in a preferredembodiment, a target assembly having a flat disk to support a targetpaper that is made of a material other than vinyl and preferably madefrom paper to yield a crisp, clean edge about a circumference of thetarget paper.

The present general inventive concept further provides, in a preferredembodiment, a target assembly having a plug or flat disk to support atarget paper, the flat disk being insertably mounted into a targetholder such that the flat disk face and target paper are slightlyrecessed into the target holder from a face surface of the target holderto protect the target paper from fingerprints, debris, and the like.

The present general inventive concept further provides, in a preferredembodiment, a plug or flat disk to support a target paper, the flat diskhaving a magnetic cover to magnetically engage the flat disk for thepurpose of trapping the target paper between the magnetic cover and theflat disk thereby protecting and/or securing the target paper.

The present general inventive concept further provides, in a preferredembodiment, a target system having an easily removable target assemblydesign to ensure correct positioning and accuracy of a target.

The present general inventive concept further provides, in a preferredembodiment, a target assembly having a plug or target body that can beremoved from a hole in the target system such that the target body canbe disassembled to replace one or more pieces of the target body such asa target paper if it becomes worn or damaged, and then reassembled andinstalled back into the target system in the exact same pre-removalposition thereby ensuring accuracy of the target assembly.

The present general inventive concept further provides, in a preferredembodiment, a target system having a target assembly with a tubular basethat is insertable into a receiver and rotatable therein.

Additional aspects and utilities of the present general inventiveconcept will be set forth in part in the description which follows and,in part, will be obvious from the description, or may be learned bypractice of the general inventive concept.

The foregoing and/or other aspects and utilities of the present generalinventive concept may be achieved by providing a target system having aelongated body with an aperature at an upper end opposite to ainsertable stand lower end, the aperture sized and shaped to accommodatea ring therein, the ring sized and shaped to accommodate a disk therein,the disk having a surface to mount a target.

The foregoing and other objects are intended to be illustrative of thepresent general inventive concept and are not meant in a limiting sense.Many possible embodiments of the present general inventive concept maybe made and will be readily evident upon a study of the followingspecification and accompanying drawings comprising a part thereof.Various features and subcombinations of present general inventiveconcept may be employed without reference to other features andsubcombinations. Other objects and advantages of this present generalinventive concept will become apparent from the following descriptiontaken in connection with the accompanying drawings, wherein is set forthby way of illustration and example, an embodiment of this presentgeneral inventive concept.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and utilities of the present generalinventive concept will become apparent and more readily appreciated fromthe following description of the embodiments, taken in conjunction withthe accompanying drawings of which:

FIG. 1 is a front elevation view of an embodiment of the present generalinventive concept illustrating an assembled target system.

FIG. 2 is an exploded cross view of embodiment of FIG. 1 illustrating atarget system with target assembly including a target disc support, atarget perimeter ring, and a target adhesive piece.

FIG. 3 is a perspective view of an embodiment of the present generalinventive concept illustrating an exploded target system.

FIG. 4 is a perspective view of an embodiment of the present generalinventive concept illustrating an exploded target system.

FIG. 5 is a perspective view of an embodiment of the present generalinventive concept illustrating an exploded target system.

FIG. 6 is a perspective view of another embodiment of a target system ofthe present general inventive concept.

FIG. 7 is a front sectional view of the target system of FIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the embodiments of the presentgeneral inventive concept, examples of which are illustrated in theaccompanying drawings, wherein like reference numerals refer to likeelements throughout. The embodiments are described below in order toexplain the present general inventive concept by referring to thefigures.

As illustrated in FIG. 1, a target system 1 includes an elongated body10 with a flat face surface 15 adjacent to a top surface 16, a convexrear surface 17 opposite to the face surface 15 that extends from thetop surface 16 to a lower surface 18, and a base 20 extending from thelower surface 18.

The elongated body 10 is generally tubular except for the face surface15 that is machined therein. An intermediate portion 21 subtly connectsthe face surface 15 to the generally tubular elongated body 10.

A circular aperture 30 extends through the face surface 15 to the rearsurface 17 and is sized and shaped to accommodate a target perimeterring 40.

The target perimeter ring 40 has a front surface 42 and a rear surface43 with a cavity 44 therein. The cavity 44 is opened at an end adjacentto the front surface 42 to receive a disc 50 and has an abutment surfacewith aperture therein. In the exemplary embodiment, the perimeter ring40 is magnetic and the disc 50 is metal such that the two elements maybe easily assembled without additional connection means. It is foreseen,however, that the perimeter ring 40 and/or disc 50 may be made of otherlike materials such as plastic, metal etc., and may be assembled withinaperture 30 using glue, epoxy, welding, etc.

The disc 50 is circular and has a flat face surface 52 and anopposite-facing rear surface 54. The flat face surface 52 is sized andshaped to receive a target paper 60.

The target paper 60 is circular and has a textured front surface 62 andan adhesive back surface 64, the adhesive back surface 64 provided tofacilitate attachment of the target paper 60 to the disk 50 face surface52.

In use, the target paper 60 back surface 52 is adhered to the facesurface 52 of the disc 50. The perimeter ring 40 is inserted into thebody 10 by sliding the front surface 42 through the aperture 30 from therear surface.

Once the perimeter ring 40 is installed, the disc 50 is inserted intothe cavity 44 by sliding the face surface 52 into the cavity 44 untilthe target paper 60 abuts an interior of the cavity 45.

In another embodiment, the disc 50 is inserted into the body 10 first,then glued or otherwise attached within the aperture 30 and then targetpaper 60 is adhered to face surface 52 of the disc 50. The ring 40 isthen installed and glued, or other wise attached, in place within theaperture 30.

In another embodiment, as illustrated by FIG. 3, the circular aperture30 may be replaced with simply a recessed portion 100 such that thetarget paper 60 nests within the recessed portion 100. Additionally, thetarget paper 60 may be covered by a circular plate 110 having anaperture 120 therethrough. The circular plate 110 fits tightly withinthe recessed portion 100. In this manner, the target paper 60 abuts botha rear surface of the recessed portion 100 and the circular plate 110,and the circular plate 110 acts to secure the target paper 60 within therecessed portion 100.

While the face surface 15 of the above embodiments extends at zerodegrees with respect to the base 20, it is foreseen that the facesurface 15 may extend at other various angles including but not limitedto forty-five degrees, as illustrated by FIG. 4, or ninety degrees, asillustrated by FIG. 5, with respect to the base 20. In theseembodiments, the target paper 60 nests within the recessed portion 100and may be covered by the circular plate 110 having an aperturetherethrough. The circular plate 110 fits tightly within the recessedportion 100 such that the target paper 60 abuts both a rear surface ofthe recessed portion 100 and the circular plate 110. In this manner, thecircular plate 110 acts to secure the target paper 60 within therecessed portion 110.

Referring to FIGS. 6 and 7, another embodiment of the inventive conceptis shown in which target system 1 includes a generally cylindrical body10 with a flat face surface 15 that is also the top surface of the body10. The flat face surface 15, of the embodiment shown in FIGS. 6 and 7,is surrounded by an annular protruding lip 616 that extends upward fromthe surface around the perimeter of the body 10. Target paper 60 isadhered to face surface 15. In a preferred embodiment, target paper 60is sized to cover approximately the entire surface of face 15. A latheand razor blade is then used to cut a circle having a diameter less thanthe diameter of face surface 15 at the center of face surface 15. Theexcess material of target paper 60 is removed from around the perimeterof the central circle, leaving a centered circle of target paper 60 asis shown in FIG. 6.

It will be appreciated that although body 10 is shown in the embodimentof FIGS. 1-5 as generally elongated, and in the embodiment of FIGS. 6and 7 as generally cylindrical, that the shape of the body 10 of anyembodiment of the instant inventive concept may be elongated,cylindrical, or any other shape desired without departing from thespirit and scope of the instant inventive concept.

Although a few embodiments of the present general inventive concept havebeen illustrated and described, it will be appreciated by those skilledin the art that changes may be made in these exemplary embodimentswithout departing from the principles and spirit of the generalinventive concept, the scope of which is defined in the appended claimsand their equivalents.

What is claimed is:
 1. A target mounting system for a retroreflectivetarget, the system comprising: an elongated body having an upper portionwith a generally cylindrical aperture at least partially therethroughand a lower tubular portion; a ring having a nest therein, the ringsized and shaped to fit within the aperture such that the ring outersurface engages an interior surface of said aperture and fits withinsaid aperture such that a top surface of the ring is generally flushwith an outer surface of said elongated body; aperture including a facesurface at an end of said aperture opposing said outer surface of saidelongated body, the ring sized and shaped to fit within the aperturesuch that at least one surface of the face engages at least one lowersurface of the ring; and a target paper sized and shaped to engage andfit between the face surface and at least one surface of the ring withinsaid aperture.
 2. The target mounting system according to claim 1,wherein the target paper is glued to the face surface.
 3. The targetmounting system according to claim 1, wherein the aperture has arecessed circular surface to support an element thereon and within theaperture.
 4. The target mounting system according to claim 3, furthercomprising a circular ring with an aperture therethrough to nest withinthe recessed circular surface with a tight fit between an outercircumference of the circular ring and a side surface of the aperturesuch that the circular ring is secured with the aperture.
 5. The targetmounting system according to claim 1 wherein said face surface comprisesa face surface of a disk sized and shaped to fit within said aperture.6. The target mounting system according to claim 5, wherein the body anddisk are made of a metallic material.
 7. The target mounting systemaccording to claim 5, wherein the target paper is trapped between afront surface of the ring and the face surface of the disk.